Why do we study Theory?
The theory of architecture is about asking two very simple questions:
· What do I want to do? And
· How should I go about doing it?
These two questions constitute the full extent of theory. For this reason theory and practice are closely related. Theory sets the attitude to practice. Practice involves doing and making things. Theory asks questions about that making, like what, where, when, why and, above all how? In this light it is impossible to practice architecture without having at least some form of theory.
The thinking that informs and decides any practical decision in architecture is called the theory of architecture. The practice of architecture uses concrete, steel, glass, wood and aluminium as its raw materials. Theory uses language. Theory too, is practice. Instead of using the materials and instruments available to the builder, the theory of anything uses the instruments of critical thought and language to perform its task.
 Michel Foucault, Language, Counter-Memory, Practice, Oxford, 1977. I first came across this important reference in Paul-Alan Johnson, The Theory of Architecture, Concepts, Themes, & Practices, New York, 1994, p. 3.